Side-by-side comparison of Type I collagen with the fundamental resonance phase data painted as an overlay on the AFM topography (left) and second
mode phase data overlaid on the AFM topography (right). The red arrows indicate
suspended fibers that absorb second resonance energy but show no fundamental resonance contrast. There are patches of contamination
(green arrows) on the glass substrate (blue arrows). The second mode
phase shows a distinct difference between the patches and the glass
not visible in the first. 4µm scan. Imaged with the MFP-3D AFM.